<html>
<head>
<script type="text/javascript">
function show()
{
	alert('123');
var t=setTimeout("show()",5000)
}
//
function timedMsg()
{
var t=setTimeout("show()",5000)
alert('over');
}
</script>
</head>

<body>
<form>
<input type="button" value="显示计时的消息框！" onClick = "timedMsg()">
</form>
<p>点击上面的按钮。5 秒后会显示一个消息框。</p>
</body>

</html>
